Help Whooping sound!!!

[mech79]

I just recently did a head Gasket and ARB studs with Cab on. Pistons were not at top dead center. I got everything back together ran the truck andf it ran great. Test drove the vehicle on a 5 mile loop and then when the owner arrived we went on a test drive again. Same loop. He took the truck home which was 50 miles and called me saying that as soon as he pulled in the driveway it was making a whooping sound. He towed it back to me and I traced it down to the noise coming out of the intake. I did the bullet proof oil cooler and egr update. How after he had it up to 100 mph and then a 50 mile drove would the valve all of the sudden bend. Could it be that the rocker arms are that weak that one snaped? I am so sick of this truck I am thinking about sending it to dealer and paying for repairs myself. Help!!!!!

[devster55]

Need a video. It's not the turbo when he let's off the gas? Stock intake?

[mech79]

He does have AFE intake system. Everything else is stock. I pulled intake tube off of throttle plate housing so turbo was eliminated. Does have AFE cover over throttle plate. I will upload video of sound tonight when I get home from work. I just can't believe that he would have bent a valve after it ran while I checked it out then two test drives and didn't show up until he got home 50 miles away. I hope it is something simple I do not want to have to pull the heads again.

[southend]

That sounds typical of a bent pushrod or rocker arm problem......

Sent from my SCH-I500

[mech79]

Here is the video I took today of the noise.

Whooping sound from intake - YouTube

[devster55]

Sounds like a bent rod.

[AshevilleEngine.com]

The original factory push rods are at the maximum edge of tolerance (too long) and when you re-torqued with the arp studs, apparently a weakened (used) pushrod eventually bent. When we re-man engines, we use an aftermarket push rod that is 50/1000 shorter than the originals. A lot of people have had lifters fail and cam shafts wiped out in these 6.0's for the same reason.

[mech79]

Where would you recommend me getting good pushrods for this guy?

[dannyboy950]

It also doesn't hurt to rotate the crank down to the 6. oclock position before torqueing down on the rockers. I know they are hydraulic lifters but it does seem to help.

All I am sayin is after I started that practice the next 30 engines we never bent another push rod. Take it for what ya think its worth.

[JUGERNAUT]

man ive never heard of that and i do at least 2 headgasket jobs a week. ive seen many times where i take the intake off and someone else has done work and dropped a nut and never found it and when you take intake of it drops into head. and sticks to the gew on the valve. when it runs look out bends valves and dents pistons. not sayin this is what happened to you. you drove truck around block and all was fine! then he gets it and bam. this is the sound of a stuck open intake valve. Push rods on these tipically shorten over time of use the dont get longer!when the rods shorten the beat the top of the lifter and break the lifter cup and the lifter retainer spring pops out this is what goes through the low pressure oil pump.when this happens the rod jumps up on the edge of the lifter and walla bent rod or broken rocker. so when you have it apart look in at top of lifter and make sure its together. hope this helps.